A widely used alarm system for advising mine workers of hazardous conditions is disclosed in U.S. Pat. No. 3,798,672 issued to Joseph Gregg, Jr., on Mar. 19, 1974. This system utilizes a plurality of sensors to detect improper or unsafe conditions such as belt tension or slippage, spillage of mined materials, high gas levels, loading car availability at belt conveyor locations, fire or the like. Detection by a sensor operates to activate a multi-track tape player and broadcast a prerecorded appropriate oral message over selectively placed speakers warning the personnel of the hazard and possible steps that should be taken to correct the condition. The patented system, while being extremely valuable in improving the safety of workers and the efficiency of the mining operations, has certain defects and disadvantages among which the most important is that should an extreme hazard and a less important malfunction occur simultaneously or immediately following one another, the tape player would switch from one track to another so as to lock out the emergency warning and broadcast only the minor malfunction message.